Physics 2 Test chapters 12 &13

Question 1

When the crystals are defective, the entire image is destroyed with this type of transducer

Answer 1

Single crystal transducer.
Mechanical transducer
Pg 167

Question 2

What’s the typical value for the electrical signal delay in a phased array transducer?

Answer 2

4-10 nanoseconds
notes and p. 172
??

Question 3

Which transducer creates a beam that is focused in all planes and at all depths?

Answer 3

annular phased array

quizlet???

Question 4

What is the advantage of using a 1 1/2 dimensional array transducer?

Answer 4

Addition of slice thickness/elevational resolution.

Pg188

Question 5

What type of resolutions are we considering with a 1 1/2 dimensional array transducer?

Answer 5

Slice thickness and
Elevational resolution
Pg 188

Question 6

What is the image shape of a vector array transducer?

Answer 6

Trapezoidal

Pg 187

Question 7

Which transducer has active elements arranged in a straight line?

Answer 7

Linear

Pg 168

Question 8

Which transducer has active elements arranged in circular rings?

Answer 8

Annular

Pg 168

Question 9

Which transducer has active elements arranged in an arched or bowed matter?

Answer 9

Convex

Pg168

Question 10

Phased array always means what?

Answer 10

Adjustable or multi-focused

Pg 170

Question 11

Linear switch transducer has what type of steering technique?

Answer 11

Also called linear sequential. Has electronic steering.

Pg 187

Question 12

What type of probe has dropout lines of image information from top to bottom?

Answer 12

Linear and convex

Pg187

Question 13

Horizontal or side to side dropout occurs in which transducer type when crystals are bad?

Answer 13

Annular phased array.

Pg187

Question 14

Which transducer is designed to be mechanically steered and fixed with single focus?

Answer 14

Mechanical

Pg187

Question 15

What is dynamic aperture?

Answer 15

“transmit hole” or “listening hole”
makes sound beam narrow over a greater range of depths
improves lateral resolution
Pg194

Question 16

What is the ultrasound machine that can display real time images and Doppler?

Answer 16

Duplex
pg 313
I just have a note I wrote in my book on pg 183 next to the bottom pic.

Question 17

The ability to accurately to locate moving structures at any time is what kind of resolution?

Answer 17

Temporal resolution

Pg 198

Question 18

What will decrease temporal resolution?

Answer 18

Deep imaging
Low frame rate
Pg 200

Question 19

Real-time imaging could be referred to as…?

Answer 19

Ultrasound “movie”

Pg 197

Question 20

What determines temporal resolution?

Answer 20

Frame rate

Pg198

Question 21

What are the factors that limit frame rate?

Answer 21

speed of sound in the medium
Imaging depth
Pg 198

Question 22

What will affect the pulses in a single image?

Answer 22

Number of focal points
Sector size
Line density
Pg 201

Question 23

If we double imaging depth, what happens to frame rate?

Answer 23

Frame rate is halved

Pg 210

Question 24

Imaging to greater depth of view requires what?

Answer 24

Long go-return time
Longer Tframe
Lower frame rate
Lower temporal resolution
Pg 200

Question 25

What will degrade temporal resolution?

Answer 25

Deeper imaging
Multiple focal points
Wide sector
High line density
Pg 209

Question 26

What is the sector size that will use the fewest pulses?

Answer 26

The narrowest sector size

p. 204

Question 27

The sonographer increases line density from 1 line to 3 lines, what will be the consequence of this action?

Answer 27

Temporal resolution decreases

p. 211

Question 28

If the frame rate is 50 Hz, how long does it take to create a frame?

Answer 28

1/50 sec

p. 214 (#23 is an example of this)

Question 29

Lateral resolution improves with what?

Answer 29

Multi-focus

p 209

Question 30

Low line density creates what?

Answer 30

widely spaced lines
fewer pulses per frame
shorter T frame 
higher frame rate 
high temporal resolution
poor spatial resolution
p. 207 (yellow box)

Question 31

What creates an image with poor movie quality but high image quality?

Answer 31

Poor temporal resolution
Low frame rate
Pg 208

Question 32

Increasing the line density degrades _____ and improves _____.

Answer 32

Degrades temporal resolution and improves spatial resolution
p. 207

Question 33

A critical factor in determining frame rate, line density and imaging depth is?

Answer 33

Time

pg 213

Question 34

If imaging depth is 15 cm and there’s 100 lines…

When frame is made quickly…how many Frames created per second?

Answer 34

100 frames per second
p. 213
???

Question 35

Using a phased array ultrasound system, if you turn off the multi-focus feature what will most likely be a consequence of this action?

Answer 35

Temporal resolution increases

pg 211

Question 36

Which of following is consistent with increased or improved spatial resolution?

Answer 36

High line density

p. 207

Question 37

When a frame is made quickly, how many frames are created per second?

Answer 37

~

Question 38

When you have 1 frame created in 1/100 second, what is the frame rate?

Answer 38

100 per second or 100 Hz

p. 213

Question 39

What are the different shapes of images for all different probes?

Answer 39

Mechanical - sector
Linear sequential - rectangle
Phased array - sector
Annular phased - sector
Convex - blunted sector
Vector - trapezoidal

Question 40

Know about steering to the right and steering to the left

Answer 40

~

Question 41

What is apodization?

Answer 41

Stronger electrical signals are used to excite inner crystals, and progressively weaker spikes excite the outer crystals then lobes are diminished
p. 193

Question 42

Focused and unfocused

Answer 42

~

Question 43

What are side lobes and grating lobes?

Answer 43

Side lobes: sound beams created by single element transducers and are additional areas of sound energy extend outside of the main beam in the far zone

Grating lobes: created by array transducers, the extra off-axis sound beams are undesirable because they degrade lateral resolution, reduce image quality, and create artifacts
p. 192